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AssigneeJozef R. C. Jansen
InventorsJozef Reinier Cornelis Jansen, Johannes Jacobus Schreuder
Estimating the term…
The segment volume of a cardiac chamber or blood vessel of a patient is determined by injecting a first indicator in the blood stream of a patient, which influences the conductance of the blood. The electrical conductance in the cardiac chamber or blood vessel is measured. An injected quantity of indicator is determined and the development of the concentration of this indicator in the blood is measured wherein the cardiac output is calculated from the injected quantity of indicator and the development of the concentration in the blood. Subsequently, the segment volume and electrical parallel conductance of a cardiac chamber or blood vessel are calculated from the calculated cardiac output, the injected quantity of conductance indicator and the measured conductance.
Method for determining the segmental volume and the electrical parallel conductance of a cardiac chamber or a blood vessel of a patient, wherein a first indicator, which influences the conductance of the blood, is injected into the bloodstream of a patient, wherein the electrical conductance in said cardiac chamber or blood vessel is measured and wherein the sum of the segmental volume of said cardiac chamber or blood vessel and the electrical parallel conductance is calculated from said conductance, characterized in that an injected quantity of indicator is determined and the development of the concentration of this indicator in the blood is measured, wherein the cardiac output is calculated from the injected quantity of indicator and the development of the concentration thereof, and wherein the segmental volume and electrical parallel conductance of a cardiac chamber or a blood vessel are calculated from the calculated cardiac output, the injected quantity of conductance indicator and the measured conductance.
Method according to any one of the preceding claims, wherein the calculated parallel conductance is used as a correction value and wherein the segmental volume is determined exclusively from the conductance signal by means of said correction value.
Method according to any one of the preceding claims, wherein the period of the heartbeat is divided into equal time segments, and wherein the segmental volume and the electric parallel conductance of a cardiac chamber or a blood vessel within the heartbeat are monitored continuously.
Apparatus for determining the segmental volume of a cardiac chamber or a blood vessel of a patient, comprising a processing unit having a control output for initiating the injection of a first indicator into the bloodstream of the patient, which influences the conductance of the blood, a first detector to be placed in a cardiac chamber or blood vessel for measuring a conductance signal, which depends on the electrical conductance at the location of the detector, wherein said processing unit is arranged for calculating the segmental volume of the cardiac chamber or the blood vessel from said conductance signal, characterized by a second detector to be placed in the bloodstream for measuring an indicator signal depending on a concentration of indicator in the blood, wherein said processing unit is arranged for calculating the cardiac output from the injected quantity of indicator and the indicator signal, and calculating the segmental volume and electrical parallel conductance of a cardiac chamber or a blood vessel from the calculated cardiac output, the injected quantity of conductance indicator and the conductance signal.
Catheter for use in a method or an apparatus according to any one of the preceding claims, characterized by a first detector for measuring a conductance signal depending on the electrical conductance, and a second detector for measuring an indicator signal depending on a concentration of indicator in the blood.
Dependencies are inferred from the claim text.